Broad frequency range with LED indicators and a buzzer This tester covers 20 Hz to 400 Hz and uses red, green and yellow LEDs plus a buzzer to deliver quick, accurate measurements for reliable electrical work. Easy and safe to use A user-friendly 3-phase rotation tester that provides precise readings to support efficient work for electricians. It is a dependable tool for safe and effective operation. Multifunctional With LED indicators and a buzzer, it can detect open phase conditions and determine phase sequence. Suitable for daily use and meeting the diverse needs of electricians. Stable performance Constructed from lightweight, durable ABS material, it provides reliable, lasting performance and safe operation across a range of electrical tasks. Typical use scenarios - Verify correct phase sequence before starting a motor in three-phase equipment. - Check for open phase conditions to prevent miswiring or motor damage. - Use during maintenance to confirm phase relationships in electrical installations.